The sky is not the limit: The past, present, and future of the Internet of Drones
Master Researcher, radio
Master Researcher, radio
Master Researcher, radio
Recently, our seminal work “The Sky is Not the Limit: LTE for Unmanned Aerial Vehicles” received the 2021 IEEE Communications Society Fred W. Ellersick Prize, which is a prestigious annual award for the best article published in any IEEE Communications Society magazine in the previous three calendar years. We appreciate the IEEE Communications Society for awarding us the prize, which is a recognition of the contributions of Ericsson people who advance communications technology.
Dr. Ismail Guvenc, Professor at the Department of Electrical and Computer Engineering at North Carolina State University, nominated the "Sky is Not the Limit" paper for the 2021 IEEE Communications Society Fred W. Ellersick Prize. Notably, Guvenc praised the contributions from Ericsson people, pointing out that, “Ericsson has been a pioneer in studying cellular-connected drones, identifying major key challenges, and developing innovative solutions.”
Guvenc continued: “In addition to their 3GPP standardization efforts, Ericsson engineers published several impactful academic papers in the literature related to mobility and interference management for cellular-connected drones. These works have been influencing academic research in this area.”
In this blog post, we present a retrospective of our “Sky is Not the Limit” journey and an outlook of the next few years about connected drones.
Figure 1: Overview of our “Sky is Not the Limit” journey.
Mobile-enabled drones
Commercial drone applications are becoming increasingly common. Drones are already widely used for newsgathering (photography and videography, for example), and for inspection and mapping in industrial applications. They are also being tested in agricultural and logistics deployments.
The potential of drone technology will only truly be unleashed when both technological capabilities and regulations allow for autonomous operation beyond visual line-of-sight. Wide-area secure wireless network connectivity is required to safely expand drone operations and unlock the potential of drone technology for commercial applications.
At Ericsson, we believe that mobile networks are well suited to provide the necessary connectivity for drones. To make sure that reliable airborne communication is possible, we have studied the connectivity performance that can be provided by terrestrial mobile networks, as well as additional capabilities that mobile networks can provide for drone operations and management.
Figure 2: Example of agriculture drone use case: surveillance of remote crops.
A journey began with 3GPP Rel-15 standardization
In early 2016, we identified that one key area to study in the 3GPP Release 15 was to enable mobile network connected drones, based on our research work (some of which was later made public in the "Sky is Not the Limit" seminal paper).
In December 2016, we submitted a new study item proposal on Enhanced LTE Support for Aerial Vehicles to the 3GPP RAN plenary meeting #74. The proposal attracted much interest, leading to the approval of the study item at the 3GPP RAN plenary meeting #75 in March 2017. The study item was supported by 35 members in 3GPP, and Ericsson and NTT DOCOMO together served as the study item rapporteurs.
The 3GPP study assessed the performance of LTE networks supporting aerial vehicles with up to the 3GPP Release 14 functionality. The study was completed in December 2017 and the outcomes were documented in the 3GPP technical report TR 36.777 including comprehensive analysis, evaluation, and field measurement results. The 3GPP TR 36.777 has become a definitive guide for mobile network connected drones, and has been widely cited by academia, industry, and regulatory organizations.
The 3GPP study concluded that it is feasible to use existing LTE networks to provide connectivity to drones, but there may be challenges related to interference as well as mobility. The challenges become more visible when the density of drones is high. Both implementation and specification-based enhancements were identified during the 3GPP study to address these issues.
After completing the study item, a follow-up work item was approved at the 3GPP RAN plenary meeting #78 in December 2017. Ericsson served as the rapporteur of the work item. The objective of the work item was to specify features that can improve the efficiency and robustness of terrestrial LTE network for delivering more efficient connectivity solutions for drones. This 3GPP work item was completed in June 2018.
In addition to the 3GPP Release 15 work on LTE Aerials in RAN, 3GPP SA studied the remote identification of unmanned aerial systems (UAS) in Release 16, and continues to investigate more aspects including connectivity, identification, tracking, application layer support, and security in Release 17.
A journey moves beyond 3GPP
After the completion of the 3GPP Release 15 work on connected drones, we have seen a surge of field trials for connected drones around the globe by major operators and vendors. Various industry organizations such as GSMA and CTIA have set up special drone interest groups to develop new use cases and help create an open and trusted regulatory environment. Besides, GSMA and GUTMA have been cooperating to align mobile and aviation industries.
The world has also witnessed growing efforts from governments to safely integrate civil and public drone operations into airspace systems. One exemplary effort is the UAS Integration Pilot Program (IPP) in the US. The IPP was concluded in October 2020, after which the Federal Aviation Administration (FAA) launched a new program called BEYOND to continue work on the remaining challenges of UAS integration.
We at Ericsson have been contributing to the relevant forums to align mobile network capabilities with drone communication and traffic management requirements. Ericsson is a full member of the Open Generation Consortium (Open Gen), which initially focuses on use cases related to operating 5G-equipped drones over the United States.
We have also seen much increased momentum in academic research in this area, which led to the creation of the IEEE Communications Society Emerging Technologies Initiative on Aerial Communications and the IEEE Vehicular Technology Society Ad Hoc Committee on Drones. We have been contributing to both initiatives since they were created.
Recently, under the NSF PAWR Industry Consortium program, Ericsson contributed cutting-edge equipment to the Aerial Experimentation and Research Platform for Advanced Wireless (AERPAW) testbed platform for 5G application testing. The AERPAW platform is designed for experimentation with drone communications. This work will accelerate research and commercialization of connected drones.
Guvenc, director of the NSF AERPAW project, said: “Our NSF AERPAW project team has been working closely with Ericsson engineers to deploy a 4G/5G NSA wireless network in Raleigh. This Ericsson network will be used by the broader wireless community in the US for advanced wireless experiments with drones. The AERPAW team is grateful to Ericsson for their help and support for academic research.”
Towards the Internet of Drones and 6G
Wide-area network coverage is needed to safely expand drone operations for beyond visual line-of-sight missions. Mobile networks can provide secure wide-area wireless connectivity, utilizing proven technology based on mobile licensed spectrum and global standards.
Already today, LTE networks can support the initial deployment of low-altitude drones. The significantly improved capabilities of 5G networks will provide more efficient and effective mobile connectivity for large-scale drone deployments with more diverse applications. As 5G rollouts continue to gather momentum worldwide, network complexity and site numbers will grow. Connected drones in turn can help to accelerate site deployment and rollout while reducing health and safety hazards, as explained for example in the blog post Afraid of heights? Drones, AI and digitalization to the rescue!.
Figure 3: Video surveillance of rural network infrastructure by drone
To further improve the 5G networks' capabilities to serve drones, we are driving the introduction of drone-related enhancements to Release 18 of the 5G NR standard. Our vision is that NR networks will become even more capable of serving drones compared to LTE networks.
The future of a connected sky with drones is exciting, despite the challenges we need to overcome on the path to 6G. To mention a recent inspiring example, the NASA’s Perseverance rover carrying a drone helicopter landed on Mars on February 18, 2021. Perhaps it is now time for researchers to consider interplanetary drone communications and networking.
As we continue the “Sky is Not the Limit” journey towards 6G, we will remain committed to working actively in the relevant forums to align mobile network capabilities with drone communication and traffic management requirements.
Our research team
Want to learn more?
Check out our award-winning article (2021 IEEE Communications Society Fred W. Ellersick Prize): The Sky Is Not the Limit: LTE for Unmanned Aerial Vehicles.
How will connected sky look like towards 6G? Read our recent article Towards 6G with Connected Sky: UAVs and Beyond to find out.